A wide variety of methods and apparatus for controlling the patterns of movement of tank and swimming pool cleaners have been disclosed in the prior art. The overriding purpose of these controls is to assure that the cleaner passes over substantially the entire surface to be cleaned during the time allotted for cleaning. In the case of tanks and above-ground swimming pools, the robotic cleaner generally makes contact only with the bottom surface of the tank or pool. In the case of in-ground swimming pools, the pool cleaner is designed to climb the side walls, typically to the water line, and then reverse the direction of movement to descend the side wall and resume a cleaning path across the bottom surface of the pool. In some wall cleaning units, the pool cleaner actually moves along the wall as part of its predetermined patterned movement so that its descent is along a different path. In many cases, the pattern of movement is random and the pool cleaner must be operated for many hours, and even then with no real assurance that some surfaces will not be missed.
As used herein, the terms “pool” and “pool cleaner” include commercial and industrial tanks, troughs, basins and the like and tank cleaners.
Pool cleaners of the prior art include those that are supported by a pair of endless tracks or belts that are independently driven by a pair of motors or by a single motor, and those that are supported on generally cylindrical cleaning brushes that in turn are driven by a system of sprockets and pulleys. The moving brushes can be made from a ribbed solid polymer web that is formed into a cylindrical supporting surface or, alternatively, from a foamed polymer material that is either smooth or highly textured and resilient.
In order to control the patterned movement of the pool cleaner, it has been the practice in the art to provide a programmed processor used in conjunction with a controller to stop, start and/or reverse the direction of the driving motor or motors. It is also known in the art to control the orientation of the pool cleaner on the surface to be cleaned by interrupting the power to the pump motor and impeller to create a torsional force sufficient to turn the entire pool cleaner body. In other cases, the processor is provided with a complex algorithm which is designed to move the pool cleaner for a predetermined period of time before changing direction or, in other cases, to cause it to move randomly across the surfaces to be cleaned with the expectation that, given sufficient time, the pool cleaner will in fact cover all submerged surfaces to be cleaner. Devices have also been disclosed that include one or more sensors for detecting a side wall or other obstruction for the purpose of generating a signal that is sent to the processor to cause some change in the operating program of the cleaner.
As will be understood by one of ordinary skill in the art, the cost associated with the design and assembly of a pool cleaner having more than one drive motor is significant. When this is combined with the expense associated with the design and fabrication of integrated circuit devices and processors embodying complex programs and algorithms and the associated controllers, it will be apparent that additional substantial expenses will be incurred. Moreover, the mechanical linkages associated with the dual drive motors are sources of wear and potential failure that require maintenance.
It is therefore an object of this invention to provide a relatively simpler and less expensive apparatus and method for controlling the direction of movement of a tank and pool cleaner as compared to those of the prior art that requires only one drive motor.
It is a further object of the invention to provide a pool cleaner directional control apparatus and method that will function in tank and pool cleaners adapted to cleaning only the bottom surface, but that will also ascend the side walls of a pool, while at the same time establishing a regular and regulated pattern of movement that will assure cleaning contact with all surfaces in a relatively short period of time.
A further object of the invention is to provide a directional control system for a pool cleaner that utilizes a relatively simple processor program, including one that can be adjusted for customized for use with a given style and/or size of pool.